"Der Mensch hat keinen anderen Wert als seine Wirkungen."
Might Schiller have meant the effect a person has, his/her influence or impact on the world or events?
In English, I believe the phrase "[a person's effects]" usually refers to a handful of personal possessions. Generally the phrase is used in the case of someone who has died in a tawdry boarding house ("The landlord bundled up his personal effects and set them out on the curb") or, perhaps, to the items one has in one's pockets when one checks into a hospital or a prison ("They put his personal effects in an envelope and gave him a receipt.") But by contrast, you wouldn't refer to Bill Gates's personal property as "his effects."
If you're using the word "effect" to talk" about consequences of a person's actions, however, you'd be more likely to say "the effect s/he has."
All of which, of course, still leaves the question as to what Schiller meant.
I think 'impact' is a good translation for 'Wirkungen' here. I'd like to see the original sentence in context as it is not entirely clear whether 'der Mensch' refers to a specific person or mankind (that's what I suspect) and whether 'Wert' refers to his own set of values or to the judgement of the world about him. I already did some research to find the source. My guess was 'Wallensteins Tod' (where such a sentence clearly would make sense) but I couldn't find it there.
So it could either mean: 'The value of a man is solely determined by his impact on the world'
or: 'This man here values only one thing: what his impact on the world is'
I suspect the former, but without the original text we can't be sure.
It's a quote from "Der Geisterseher" (The Ghost-Seer).
I've had a quick look at Grimms' dictionary and to me it seems that "actions" is a better fit than "impact".
@christian: thanks a lot. »Lassen Sie uns diesen Ausdruck vermeiden, der uns irre führt. Sagen Sie, er ist da, weil die Ursachen seines Daseins da waren und weil seine Wirkungen existieren, oder, welches ebensoviel sagt, weil die Ursachen, die ihm vorhergingen, eine Wirkung haben mußten, und die Wirkungen, die er hervorbringt, eine Ursache haben müssen.«
›Wenn ich ihm also einen Wert beilegen will, so kann ich diesen nur nach der Menge und Wichtigkeit der Wirkungen abwägen, deren Ursache er ist.‹
»Nach der Menge seiner Wirkungen. Wichtig nennen wir eine Wirkung bloß, weil sie eine größre Menge von Wirkungen nach sich ziehet. Der Mensch hat keinen andern Wert als seine Wirkungen.«
As he talks about cause and effect here, I think I'd still vote for 'impacts' or 'effects' in the sense of a causal relationship.